Nowadays, IC tags are considered products opening the ubiquitous era and they have been developed for use as RF-ID (radio frequency identification) in nametags, Suica cards, FeRAM cards, or the like. Many people expect that the market of IC tags will surely grow into a large one. However, the current IC tag market is smaller than expected because of problems requiring social efforts to solve, such as issues regarding price, security, and confidentiality.
Prices of IC tags can be lowered by reducing the sizes of IC tag chips, because the smaller IC tag chips are, the more IC tag chips can be obtained from a wafer. The smallest IC tag chips to date have dimensions of 0.4 millimeters square, and from such IC tag chips, 128-bit memory data can be read using microwaves of 2.45 GHz frequency (e.g., see Non-patent Document 1).
A known method for manufacturing an IC tag chip is described in, for example, the “Related Art” section of Patent Document 1. In this manufacturing method, the backside of a wafer having an IC on the foreside is ground by backgrinding so that the wafer has a reduced thickness, and then the wafer is diced into many IC tag chips each having a predetermined shape. In this dicing step, a dicing saw is used to cut and separate a wafer into many IC tag chips.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2003-179005
Non-patent Document 1: Mitsuo Usami, An ultrasmall RFID chip: μ-chip, OYO BUTURI, Vol. 73, No. 9, p. 1179-1183 (2004)